1. Field of the Invention
The invention relates to a round-bale press for stalk-shaped crops.
2. Background Information
Round-bale presses of this type are known, for example, from European Patent Application 235,787 or 296,665. In these, at the start of winding of the bale the press chamber has, in longitudinal section, approximately the form of a segment of a circle, the chord being formed by the front strand, inclined only slightly forwards relative to the vertical, of a pressband arrangement, and the circle arc being formed by a series of rollers arranged with fixed axles. In the examples mentioned from the state of the art and also in the subject of the application, the press-band arrangement consists of a plurality of endless belts or bands rotating at mutual distances next to one another. However, the concept also embraces corresponding arrangements of chains, ropes or similar lines.
The press space of these known round-bale presses is limited downwards by a pick-up roller or by this and a ground roller additionally conveying rearwards. The inlet orifice for the crop to be pressed is located between this ground arrangement and the bottommost roller of the front termination having the form of an arc of a circle. With increasing bale size, the press-band arrangement shifts aside rearwards. Finally, the bale is discharged by opening a rear flap, on which the deflecting roll or rollers of the pressband arrangement are mounted.
In these known round-bale presses, the empty press space is relatively large, and therefore the initial bale is formed in a more or less "uncontrolled" manner and only after a relatively large quantity of the crop for pressing has been introduced. Too little volume pressing consequently occurs in the central region of the bale, and the result of this can be that the latter is not truly circular or loses its shape during subsequent transportation and stacking.
It is known from European Patent Application 339,730 to reduce the initial press space by designing the roller arrangement forming the front circumferential limitation of the press space so as to be pivotable forwards and backwards about one of the lower roller axles. The roller arrangement has an upper non-driven roller which runs behind the front strand of the press-band arrangement, so that the pivotable roller arrangement is suspended on the said strand and, when the latter is stretched at the start of formation of the bale, is inclined rearwards towards the interior of the press chamber and reduces this. However, the roll formation is only slightly assisted thereby, since a true rotation of the crop for pressing occurs only when a particular internal pressure has built up in the reduced press chamber as a result of the quantity of crop introduced.
Finally, it is known from prospectuses of the Italian firm of L. Sgorbati, instead of rolls, to arrange in groups fixed conveyor bands running over at least two deflecting rollers, for the front and lower circumferential limitation of the press space.